A SPAN lab research effort to develop a open source, GNU Radio-based channel sounder has led to a publication that is now published. The paper, "Channel Sounding for the Masses: Low Complexity GNU 802.11b Channel Impulse Response Estimation" has been published in the IEEE Transactions on Wireless Communications. It appeared online on the 1st of December, 2011. The paper is authored by Dustin Maas, Mohammed H. Firooz, Junxing Zhang, Neal Patwari, and Sneha K. Kasera. The image to the right shows one of the central ideas of the work: Typically, channel sounders have used unmodulated pseudo-noise (PN) sequences as signals. In this paper, modulated PN signals from standard 802.11b sources are used. Because of the modulation, the cross correlation with the PN signal is not ideal, so one must take care in the channel sounder design.